452 MISC. PUBLICATION 200, TJ. S. DEPT. OF AGRICULTURE 



2.5 cm long. % (A. reverchoni Vasey.) — Dry or rocky hills and 

 plains, Texas to Utah, Nevada, and southern California, south to 



Puebla, Mexico (fig. 969). 

 23. Aristida purpurea 

 Nutt. Purple three- 

 awn. (Fig. 970.) Per- 

 ennial, often in large 

 tufts; culms 30 to 50 

 cm tall; blades usually 

 involute and less than 

 10 cm long, 1 to 1.5 mm 

 wide when unrolled; 



Figure 



-Aristida spiciformis, X 1. 

 1115, Fla.) 



(Combs and Baker 



the body tapering to a scarcely beaked 

 summit, tuberculate-scabrous in lines 

 from below the middle to the summit; 

 awns nearly equal, spreading, 3 to 5 cm 

 long. % — Dry hills and plains, Arkan- 

 sas and Kansas to Utah and southern 



Figure 967.— Distribution of 

 Aristida spiciformis. 



panicle narrow, nod- 

 ding, rather lax and 

 loose, usually purplish, 

 10 to 20 cm long, the 

 branches and longer 

 pedicels capillary, more 

 or less curved or flexu- 

 ous; first glume 6 to 8 

 mm long, the second 

 about twice as long; 

 lemma about 1 cm long, 



Figure 969.— Distribution of 

 Aristida glauca. 



California, south to northern Mexico 

 (fig. 971). Aristida purpurea var. 

 laxiflora Merr. Panicle few-flowered, 

 the capillary branches bearing 1 or 2 

 spikelets. % — Texas to Arizona. 



24. Aristida roemeriana Scheele. (Fig. 972.) Differing from 

 A. purpurea chiefly in the smaller spikelets; first glume 4 to 5 mm 



Figure 968.— Aristida gtauca, X 1. 

 (Reverchon 1237, Tex.) 



